Pump



May 19,1959 1.. L. ASPELIN 2,887,063

' PUMP Filed March 17, 1954 I 3 Sheets-Sheet 1 Ecgni May 19, 1959 1.. L. ASPELlN PUMP Filed March 17, 1954 s Sheets-Sheet 2 mar/ll! [III E27 2271* 1561/5 L 4.52 54 //v & g ,fi'mm qbwu 17172 75.

May 19, 1959 L. L. ASPELIN -2,887,063

PUMP

5 Sheets-Sheet 3 Filed March 17, 1954 United States Patent PUMP Leslie L. Aspelin, Cleveland Heights, Ohio, asslgnor to Thompson Ramo Wooldridge Inc., a corporation of Ohio Application March 17, 1954, Serial No. 416,792

2 Claims. (Cl. 103-126) This invention relates to a pump especially useful for power steering apparatus or the like to supply a relatively constant rate of flow of liquid at a predetermined pressure regardless of wide variations in operating speeds. Specifically, this invention relates to a unit adapted to be easily attached to the rear face of an automobile engine generator and having a pinion and ring gear pump therein driven from the generator and submerged in the fluid which it pumps to flow control and relief .valves that deliver a rated flow of fluid from the unit at less than a predetermined maximum pressure throughout a wide range of pump speeds while storing and cooling excess fluid in the unit.

While the pump of this invention will be hereinafter specifically described as embodied in a power steering apparatus for an automobile, it should be understood that the pump of this invention is generally useful in pumping hydraulic fluid at a substantiallyconstant rate and at less than a predetermined maximum pressure regardless of the speed of operation of the pump. The feature of submerging the pump in a bath of the liquid which it pumps, is applicable and especially useful in power steering apparatus to provide a reservoir for the hydraulic liquid, such as oil, to lubricate the pump and to cool the liquid.

In accordance with this invention a rotary pump of the rotating ring gear and pinion type is mounted inside of a finned housing from which it receives liquid to be pumped. The pump casing has an end head with a peripheral groove. The end head is adapted to be abutted against the end face of the generator and a clamping ring locked in the groove attaches the unit to the generator. A hollow hub carried by the end head is adapted to receive, in splined relation, a drive shaft from the generator. The pinion of the pump is keyed on this hub. Fluid is fed from the bottom portion of the housing through a side face of the gear and pinion into the tooth chambers and is discharged from the tooth chambers out of the opposite side face of the assembly .into a passageway containing a spring biased orificed valve. This valve controls the rate of discharge from the pump and whenever the pressure differential on opposite sides of the orifice thereof exceeds a predetermined value,

the valve will be shifted to uncover a port communicating with the interior of the housing for dumping the pump fluid back into the housing from which it was received. The outlet passage from the pump also is vented to a pressure relief valve communicating with the interior of the housing so as to protect the pump and the system in which the pump operates against excess pressure. Fluid at the working pressure and at the working rate is thereby discharged downstream from the orificed valve and from the relief valve to be conveyed by a tube to a power steering actuator or the like. The fluid is returned through a second tube back to the housing from which it is again recirculated to the pump. The fins on the housing will radiate heat from the flfluid. The fluid will also lubricate the pump, and the housing,

. merged pump assembly adapted to be clamped on the back face of an automobile generator to be driven thereby and having a metering valve and a relief valve for controlling the flow. rate and the maximum pressure developed by the pump.

Another object of this invention is to provide a power steering pump having its own hydraulic fluid reservoir adapted to be mounted on a generator of an automobile engine to be driven by the generator and adapted to cool the hydraulic fluid. I

A still further object of this invention is to provide a pump of the rotating ring gear and pinion type receiving fluid to be pumped through one side face and discharging the pump fluid through an opposite side face to a flow control valve adapted to dump excess fluid into a reservoir surrounding the pump while maintaining a constant delivery rate for the pump.

A still further object of this invention is to provide a submerged rotating ring gear and pinion type pump having an inlet on one side face thereof receiving liquid from the bottom of a reservoir and having an outlet. on

the opposite side face delivering the fluid to adischarge passageway containing an orificed metering valve which will dump excess liquid back to the reservoir to be cooled therein before being recirculated to the pump.

Other and further objects of this invention will be apparent to those skilled in the art from the following detailed description of the annexed sheets of drawings which, by way of a preferred example only, illustrate one embodiment of the invention.

On the drawings:

Figure l is a somewhat diagrammatic elevational view of a pump of this, invention mounted on the generator of an automobile engine for supplying working liquid to a power steering apparatus for the vehicle which is driven by the engine.

Figure 2 is an enlarged front end elevational view of the pump along the line II-II of Figure 1..

Figure 3 is a longitudinal cross-sectional view of the pump taken along the line III--III of Figure 2.

Figure 4 is a cross-sectional view, with parts in elevation, taken along the line lV-IV of Figure 3.

Figure 5 is a cross-sectional view, with parts in elevation, taken along the line V--V of Figure 3.

Figure 6 is a cross-sectional view taken along the line -.VI-VI of Figure 3.

As shown on the drawings: In Figure 1, the pump 10 is shown as mounted on a generator 11 of an automobile engine 12. The engine 12 has a crankshaft driven pulley 13 driving a fan belt 14. a .The belt 14 drives the fan pulley 15 for rotating the fan A pulley 17 on the generator 11 engages the fan belt 14 to be driven thereby. The generator shaft 18 is joined by a coupling 19 to the pump shaft 20.

As best shown in Figure 3, the pump casing 21 has a ,large end head 22 at one end thereof bolted to the main body 23of the pump by means of bolts such as 24 shown in Figure 4. The end head 22 has an external V-groove 25 around the periphery thereof adjacent its flat outer face 26 and this flat outer face 26 is adapted to abut the flat outer face 27 of the generator housing which also has a,

V-shaped groove 28 therearound. A clamping ring 29 ex-tends'into both groovesZS'and 28 tolock the end head on the generator and thereby" mounts" the pump: This clamping ring 29 can be tightened by the means of the usual drawbolt clamp 30 or the like.

' The pump'ca'sing21 is" enclosedby anouter'housing' 31* of substantially cup-shape with an open end' 32'receiving the end head 22 ofthe pump; A groove 33 in this end receives a sealing'ring34 for'sealingly engaging'the inner face'of the housing adjacent the'open end'32.

Longitudinal cooling fins3'5- radiate from the housing 31 around'the periphery thereof. A filling port 36 is provid'ed in the topof the housing and is closed by a snap-in cover37L The'closed end wall' 31a of'the housing 31 has bosses 38' and 39'therein carryingfittings 40' and 41. The fitting 40'isthrea'ded into a discharge passage 42 formed in the casing body 23. Thefitting 41 communicateswith the interior of the housing'31 near the bottom thereof.

The end head 22 has a central hub portion 43 with an enlarged outer'bore 44 terminating at a shoulder 45 and carrying a seal 46 against the shoulder. A smaller bore 47 continues inwardly from the shoulder and carries roller bearings 48 for rotatably supporting a hollow shaft 49 with spline teeth 50 in the interior thereof intermediate-the ends. The shaft extends beyond the end head 22 into a recess 51in the body 23 and roller bearings 52 are seated in this recess to carry the shaft extension. A knurled plug 53 is pressed fit into the end of the shaft 49 adjacent the bottom of the recess 51 to seal the interior of the shaft from'the recess.

A pump pinion 54 is keyed on theshaft 49 intermedi-- ate the ends thereof 'by means of a key 55 and a pump ring'gear 56 surrounds the" pinion 54.

The inside face 57 of'the end head 22 receives one side face of the'pinion 54 and ring do'thereagainst and an arcuate inlet port 58' in this end face is connected through a passageway 59 in the end head'with theinterior of the housing 31 at the bottom thereof. The mouth of this passageway is covered by ascreen 60. A blind arcuate' recess 61 is also provided in the end face 57in opposed'relation to the port58. The main body 23 has" an outlet opening 62 opposing the port 61 on the opposite face of the ring and'pinion and communicating with the discharge passageway 42.

The pinion 54 and ring 55 fit in a recess 23a in the'end face of the body 23 adjacent the end head 22.

As best shown in Figure 6, the pinion has external teeth 54:! around its @periphcry'and the ring gear has mating teeth 56a around its inner periphery with the pinion containing one less tooth than the ring gear. The tooth shape is such that during rotation of the two gears, a plurality of expanding and contracting pumping chambers 63 is formed in the inter-toothspaces.

When the shaft 49 rotates the pinion, the ring gear is driven from the teeth 54a of the-pinion and liquid enters into the open pumping chambers 63 along the extent of the inlet port 58. The axis of the shaft 49'on whichthe pinion is mounted is eccentric to the bore recess 23:: of the housing 23 in which the ring gear rotates and liquid is trapped in the pumping chambers 63 to be propelled to the outlet ports 61 and 62. The provision of the port 61 opposite the outlet port 62 balances the load on opposite faces of the ring gear and pinion and provides a smooth discharge of liquid. The liquid is ejected as the pumping chambers 63 are reduced in volume due to the mated engagement of the teeth and it will be noted'that asthe teeth leave the outlet ports; they are-in fully mated relationship so as to seal the. outlet from the inlet ports. As the teeth enter the inlet port they become mismated to open up the pumping spaces therebetween and as they continue between the 'inlet and outlet ports, the apices of the teeth sealingly engage each other to maintain the trapped fluid therein.

The. outlet. passageway 42 of' the pump slidably'receives a spring 64 loaded flow control valve 65 in the.

4. form of a thimble with an orificed end wall a having an orifice 66 therethrou'gh sized for maintaining a predetermined pressure drop between the upstream and downstream sides thereof. The valve 65 slides in the bore of the passageway to cover and uncover a port 67 communicating with the interior of the housing 31 and, as the valve uncovers this. port, fluid will be returned from the passageway 42 back to the interior of the housing. The port 67 is vented at68 to the recess 51 so that any pressure exertedion. the end' of the'pump shaft due.

to leakagefrom thev pump will be. vented to inlet and will not provide a thrust load on the assembly.

A port. 69 in the passage 42 downstream from the valve 65 is connected through a passage 76 in the body 23 with a bore 7.1 in the-front wall of. the body 23. A valve seat 72 is formed at the bottom of the bore 71 and a ball member 73 in a carrier 74 which is slidable in the bore 71, is spring-urged by a spring 75 against the seat to control flow from the passage to an outlet 76 communioating' with the' interior of the housing. A plug. 77

is threaded into the bottom of the bore 71 to bottom the spring The plug'can be adjusted to vary the spring load for varying the load at which the valve 73 will open.

Operation In operation, hydraulic liquid to operate the power' steering apparatus'78 of Figure l. is introduced into the.

housing 31 to substantially'fill the housing and thereby surround the pump body 23. This liquid will cover the inlet 59 and when the engine 12 is operated to drive the. generator 11, the pump shaft 20 will rotate the pump shaft hub 49 to thereby drive the pinion 54. The pinion,

in turn, drives the ring gear 56 and the liquid is propelled to the passageway62 where it acts on the end face 65a of the valve 65 and partially depresses this'valve against the action ofthe loading spring 64. Fluid flows through the orifice-66 and is'delivered through the fitting 40 to a feed tube 79 into the actuator 80 of the power steering.

apparatus 78. A valve (not shown) in the power steering apparatus; is'controlled by thesteering wheel 81 on the steering column 82' and this valve regulates the admission and release of thefluid to the actuator. Thepitman arm 84 is thereby power driven from the power steering apparatus 78.

A return tube 85' returns'the liquid to the fitting'41 which deposits it back to the housing 31. In the event that the actuator 89 is inactive and does not require fluid for operation, the pressure difiercntial across the valve 65 will in'creaseto further depress the valve against the load of the-spring 64, thereby opening up the port 67 to returntheliquidback to the interior 'ofthe housing. The degree-of openingof the port will determine the relative proportion ofliquid fed to the feed tube and the proportion returned to theinterior of'the housing. In the event that back pressure exceeds a predetermined maximum, the check valve'73- will be" opened to relieve the pressure downstream from the flow control valve.

The feature of *providing the inlet port 58 and the outlet 62 of the pump on'opposite. sides of the pinion and ring.

gear, affords a very compact balanced arrangement.

The feature. of submerging the pump in the hydraulic liquidand the-placing of cooling fins on the housing for.

the pump, maintains the hydraulic liquid in a cooled condition.

Therpump: of this: invention. is; therefore; adapted. to deliver'fluid at an essentially constant tr'atetto the actuator of; the:- power. steering apparatus. without developing excess' pressures regardless of thevariedispeed" of operationa When the pump is operated at slow speeds due to the idling" of. the engine 12, the flowmetering valve 65 will be closed. As the-engine spcedincreasexthe'valve will be partially'opened' to relieve excess flow back" to the pump interior.

Itwill' be understood that variations. and modifications.

may be effected without departing from the scope of the novel concepts of this invention.

I claim as my invention:

1. A pump adapted to be detachably mounted on an automobile engine driven generator to be driven from the engine through the generator shaft for supplying fluid under pressure to fluid motor means which comprises a cylindrical end head having a peripheral mounting groove therearound adjacent a first face thereof and a peripheral seal ring groove therearound adjacent the opposite second face thereof, a pump body of smaller diameter than said end head having a first end face abutting the second face of the end head, said pump body and said end head having aligned bores, said pump body having a recess in the first end face thereof surrounding said bore in the body, bearings in each bore on opposite sides of said recess, a pump shaft mounted on said bearings, a pump rotor in said recess driven by said shaft, said end head having an inlet in said second face joined with said recess, said body having an outlet passage joining the recess with a second end face of the body, a cup-shaped housing having the open mouth thereof seated over the end head around the seal ring groove thereof and terminating short of the mounting groove, a seal ring in the ring groove sealingly engaging the mouth of the housing, said housing having the closed end wall thereof abutting the second end face of the body, said housing end wall having a first opening aligned with the outlet passage of the body and a second opening spaced from the body, an outlet tube fitting extending through the first opening and threaded into said outlet passage, a flange on said outlet tube fitting abutting the outer face of the housing end wall to clamp the housing to the second end face of the body and hold the housing on the end head, an inlet tube fitting threaded in said second opening, and said housing having a filler opening to admit fluid for submerging the pump body and for covering the pump inlet in the end head.

2. A pump adapted to be detachably mounted from an end head thereof which comprises an end head having mounting means thereon adjacent a first face thereof and a peripheral seal ring groove therearound adjacent the opposite second face thereof, a pump body of smaller diameter than said end head having a first end face abutting the second face of the end head, said pump body and end head having aligned bores, a pump recess surrounding a bore,

hearings in each bore on opposite sides of said recess, a pump shaft supported on said bearings, a pump rotor in said recess driven by said shaft, said end head having an inlet passageway with an inlet port in said second face externally of the pump body, and said passageway being joined with said recess, said body having an outlet passage joining the recess with a second end face of the body, a cup-shaped housing having the open mouth thereof seated over the end head around the seal ring groove thereof and terminating short of the mounting means, a seal ring in the groove sealingly engaging the mouth of the housing, said housing having the closed end wall thereof abutting the second end face of the body, said housing end wall having a first opening aligned with the outlet passage of the body and a second opening spaced from the body, a flanged outlet tube fitting extending through the first opening and threaded into said outlet passageway with the flange thereof thrusting against the outer face of the housing end wall to clamp the housing to the second end face of the body and to hold the housing on the end head, an inlet tube fitting threaded in said second opening, and said housing having a filler opening to admit fluid for submerging the pump body and for covering the pump inlet in the end head.

References Cited in the file of this patent UNITED STATES PATENTS 2,063,937 Kundig Dec. 15, 1936 2,393,406 Parsons Jan. 22, 1946 2,413,040 Elliott Dec. 24, 1946 2,440,948 Hawkins et a1. May 4, 1948 2,603,065 Sarto July 15, 1952 2,661,696 Dale Dec. 8, 1953 2,707,375 Hammond May 3, 1955 2,724,335 Eames Nov. 22, 1955 2,742,862 Banker Apr. 24, 1956 2,752,853 Eames July 3, 1956 2,759,423 Keel Aug. 21, 1956 2,818,813 Pettibone et al. Jan. 7, 1958 2,827,854 Huber Mar. 25, 1958 FOREIGN PATENTS 740,738 Great Britain Nov. 16, 1955 

